The relationship between vestibular function and visuospatial ability in adults aged fifty-five and older

In this study, it is aimed to investigate the relationship between vestibular function and visuospatial ability in adults aged 55 and older, and to determine whether there is a difference in terms of vestibular function between adults aged 55 and older, divided into two groups according to Mini Mental State Examination scores. Adults aged 55 years and older with Mini Mental State Examination scores of 20-24 and adults with Mini Mental State Examination scores of 25 and above were included in our study. Cervical Vestibular Evoked Myogenic Potentials (sVEMP) Test, Ocular Vestibular Evoked Myogenic Potentials (oVEMP) Test, Videonystagmography (VNG), Video Head Impulse Test (vHIT), and Mental Rotation Test were administered to the participants. No statistically significant difference was found between the groups in terms of Mental Rotation Test response time (p>0.05). The number of correct answers to the Mental Rotation Test of the control group was statistically significantly higher than the study group (p=0.001). In sVEMP and oVEMP tests, there was no significant difference between the groups in terms of P1 latency, N1 latency, P1-N1 interlatency, P1-N1 amplitude, interaural amplitude asymmetry ratio and wave response rates in the right ear and left ear at 110 dB nHL (p> 0.05). In the sVEMP test, a statistically significant positive correlation was obtained between the left ear P1-N1 amplitude at 110 dB nHL in the study group and the Mental Rotation Test response time (r=0.571, p=0.013). A statistically significant positive correlation was found between left ear N1 latency (r=0.473, p=0.035) and right ear P1 latency (r=0.539, p=0.012) and Mental Rotation Test response time in the control group. In the oVEMP test, there was a statistically significant negative correlation between left ear P1-N1 interlatency at 110 dB nHL in the study group and the number of correct answers in the Mental Rotation Test (r=-0.638, p=0.047). In the control group, a statistically significant negative correlation was found between left ear P1-N1 interlatency and Mental Rotation Test response time (r=-0.650, p=0.006). In videonystagmography, saccadic latency, accuracy and speed, pursuit test gain and asymmetry, optokinetic test, right and left eye gain were evaluated against stimuli flowing at a rate of 30°/sec to the left and right in both groups, and there was no significant difference between the two groups in terms of parameters evaluated except the average accuracy percentage of the left eye to the right (p=0.008) and the right eye to the right gaze (p=0.014) saccadic eye movements (p>0.05). In the study group, a statistically significant positive correlation was found between the latency values of the saccadic eye movements and the number of correct answers in the Mental Rotation Test in the right eye right gaze (r=0.428, p=0.029) and right eye left gaze (r=0.396, p=0.045). There was a statistically significant positive correlation between the right eye gain value at 0.1 Hz (r=0.429, p=0.029) and 0.4 Hz (r=0.433, p=0.027) in the pursuit test of the study group and the response time of the Mental Rotation Test. There is a statistically significant negative correlation between left eye asymmetry percentages at 0.1, 0.2 and 0.4 Hz, and right eye at 0.1 and 0.2 Hz, and Mental Rotation Test response time (p<0.05). A negative correlation was found between the gain values of the left eye at 0.2 Hz, the right eye at 0.2 Hz and 0.4 Hz and the number of correct answers in the Mental Rotation Test (p<0.05). There was also a positive correlation between left eye asymmetry percentages at 0.2 Hz, 0.4 Hz and the number of correct answers in the Mental Rotation Test (p<0.05). In the pursuit test of the control group, there was a statistically significant negative correlation between the percentage of left eye asymmetry at 0.1 Hz and the Mental Rotation Test response time (r=-0.434, p=0.027). In the control group, there was a statistically significant positive correlation between the gain values in the left eye (r=0.507, p=0.008) and the right eye (r=0.561, p=0.003) against stimuli flowing to the right at a rate of 30°/sec, and the gain values in the right eye (r=0.503, p=0.009) against the stimuli flowing at a rate of 30°/sec to the left, and the Mental Rotation Test response time. In the Video Head Impulse Test (vHIT), there was no statistically significant difference between the groups in terms of lateral and vertical canal VOR gain averages (p>0.05). There was a statistically significant negative correlation between left anterior SSC VOR gain and Mental Rotation Test response time in the study group (r=-0.504, p=0.009). There is a statistically significant positive correlation between the right posterior SSC VOR gain and the number of correct answers in the Mental Rotation Test (r=0.459, p=0.018). There was a significant negative correlation between the right lateral SSC VOR gain and the number of correct answers in the Mental Rotation Test in the control group (r=-0.407, p=0.03). In conclusion, in our study, no difference was found between adults with Mini Mental State Examination scores between 20-24 and 25 and above in terms of vestibular function, except for average accuracy percentage of the left eye to the right (p=0.008) and the right eye to the right gaze (p=0.014) saccadic eye movements (p>0.05). There is no study in the literature evaluating the relationship between the vestibular test parameters, the Mental Rotation Test response time and the number of correct answers. More studies are necessary in order to interpret the findings accurately. This study will contribute to the current literature on the vestibular and cognitive system.